Rheostat.



' .certain new y Rheostats, of which the following is a speciu ini-TED 'sTATEs PATENT orario" encuen-.lH. DoRGELoH, or sorrENRcTADYgNE-Wv-YORK, AssmNo-R To GENERAL. l ELECTRIC coMPANY, A CORPORATION or NRW YORK.

RHosTA'r.

.Specification of Letters latent.

Patentedllo'v. 30, 1,999.,

Application area Jamie-190s. serial No. 437,753.

To all whom fit may concern: l

Be it known that I, GEORGEH. DoRGnLoH, a subject of the Emperor offGermany,` -residing at Schenectady, county of Schenectady, State of. New-,Yorln have 'invented and useful Improvements in cation; l This invention relates to means for controlling electric motor ci'rcults4 and has for its object the provision of a device of this character .whereby a motor may be vbrought:

upto running speed n a reliable and letlicient-manner and at the same time is freeA from 'dangerof injury by' abnormal conditlons of the circuit or carelessness of the.

i' operator.

i In carrying` out/myE invention I vprovide in connection with a starting resistance, an unbiased controlling arnnthatisone which may be left upon any lof the starting con-w tacts. This coi'itrollingvarm is se interlocked with` an automatic c ircuitfbreaker that the latter cannot be closed until the arm is moved to'startingpos'ition. The under-load coilof the circuit-breaker is controlled by the starting'armindependently of the m'ove'- ment of the arm over the starting contacts, that is the handle of the controlling arm must be held in-a definite position in order to energize the underloadboiland 'keep'the circuit-breaker closed. lf ,the 'operator on. any intermeenergized and` the circuit will be opened.

In order to 1na.intaintlie 'circuit-breaker closed when vthe controlling arm is in "running position I provide a latch which co'. operates with the arm to control the underload coil. The 'arm is provided with: a short-cireuiting brush vwhich eoperates with stationary contacts to short-circuitthe con` trollin arm when t-he running position is reacheil and the latch is'arranged so as to grasp the arm and 'firmly holdfthe brush against'thecontacts, y

.l Other objects of my invention will ap- `pear .in the course'of the following specilication :in which 'I have shown the invention embodiedin concreteA mechanism for 'purposesof illustration.

, In the drawings, Figure 1 represents 'a plan view of the rheostat embodying my invention; Fig. 2 represents asectional view of the same; Fig. 3 -shows a detail ofthe latching mechanism for v the arm; Fig- 4t 4shows the interlocking'mechanism between the arm and the circuit-breaker; and F ig. 5 is av diagram of the circuits.

Referring to the drawings 10 is a baseor panel-board of some insulating material,`

such as slate or soapston'e, having mounted thereon 1n an arc of a circle a plurality of contacts 11 forming terminals for the start-l ing resist-ance 12 lThese .contacts are ar-.'v

lranged to be engaged by contactvstrips forming a clip 13 mounted upon the underside of the controlling' arm 14. y[This arm is pivoted at. 15 and is unbiased so that it may be left upon any of the contacts as desired.- An automatic circuit breaker 16 is mounted uponlthe panel-board adjacent to thetirst of the Starting cont-acts. This circuit-breaker isl of a" standard type and forms nopart of myinvention.- The particular type of circuit-breaker'l pole 'typeV having the arms arranged for in ,dependentmovement. The starting rheostat and the `circuit-breaker are so interlocked that the latter cannot be closed until the controlling arm is moved tostartino 'pesition. Thel arrangement 'whereby' tlnsb object isjattained is described and claimed in the patent to Yatesv an'd'FenWick No. 793,493. Generally speaking the circuit-breakcr lis prevented Afrom closing by a spring-pressed pin 17 which projects upward through the base so as to vengage one arm of the circuit: breaker and prevent its closing. Avrod 18 is mounted beneath the panel so as to slide longitudinally and is provided opening 19 through which the pin 1T may be forced.. when the rod is moved-so 4as to make the openinfr register with vthe pin. This movement of the rod isl effected by a member 20 projecting through the panel into the .the arm may force it in Y one "direction while a vsprlng 21 will ret-urn to the position prefer to use Ais the doublewith an path of the controlling arm so that shown in 'Fig..t.' Y The underload coil 22 of 100 the circuit-breaker having a .series therewith has one end connected with a contact segment 23 'ahile theother end is connected with one vof -the circuit-'breaker contacts. This segment islarranged to be engagel by a contact. finger 24 pivoted upon resistance y R in the arm ifi so as to move at. right angles 'i thereto. The handle has an extension 2o Ywhich pa through the arm so to give it a si-zyivcling motion. The inger 2li is mounted upon this projection a spring 2T holds the. handle in he position shown in Fig. so that the linger 2 is normally ont of contact with the segment Q3. By twisting' the handle, however, the finger may be io brought into contact with the segment and the contact will immediatelybe breiten When the handle releases. A. laminated Contact brush 28 mounted upon the ao lli so as to engage the :lifted contacts 22) when the 'l5 arm is the running position. ln order to' press the brush, 'which is slightly yielding, into engafeinent With the contacts, li provide a latch 3() pivoted open the base in bracket This latch is normally'spring- 2O pressed so that its hook or engogingportion is forced upv-fard. llilhcn the arm is' jorced eter the latch and the brush is firmly presse l against the contacts, the arm will be anto-` matically latched in position shown in lug.

3. In order to malte it possible to Arelease the handle when the arm' is in running;` position andv still maintain the circuit. with the `nndcrload coil closed connect. the latch with the underload coil so that the circuit 1,10 of the coil may be closed between thcbrackct sinon which the latter is mounted and the arm. lhis likewise assures the opening of the. circuit-brenker when the erm leaves running' `position.

"T5 Tl' arrangement ot circuits and mode of nnorz'nion nre :is follows: In order to start the ilniior, the arm is first brought to 'the starting vgosition so that the circuit-breaker may bc closedi yihc ooerator then grasos '1Y0 the handle and by turning it in a clockwise direction upon the firm, contact i made bctween the segment am. ii L? ll so that the rio-voltage coiA l ed 'trom the posit: Je main to segment finger to the rivoli i5 and baci; to the ncgativ'c main through the other arm of the circ!itt-breaker. The circuit-breaker is thus' kept closed While the operator moves the arm to the running position. lf, however, he should carelessly leave the arm in any et the internimliate positions so as lo endanger the res'-itni'ice, 'the nndcrload coil will inin'lcdiatcly be deencrggized. lt will then be necessary lo retnrnrthcarni to position bc'hrc the enit can ch atched` there and engage ntwith ovation snehandlc 'lllin c icc the latter is non` ettore-ized from 'the segment Q51 through conductor and crm l-l. it' the circuit breaker should open oy reason of normal conditions on the circhi" the nrm must he returned to storting pos.- if

55 tion bciore the circuit can be again closed.

By' this arrangeinentfgthe controlling arm is normally held in running position and will not he moved by a1-ring orby accidentally striking it since it must, be positively released from the latch. The armature circuit also closed independently of the starting contacts andthe short-circuit-ing switch is pressed into hrm engagement with the contacts so as to make a'lirin and cli cient contact.

lfVhile l have described myinvention in connection with cert-ainy Sp'ecilie structural features and arrangement of circuits, it should be understood that l do not limit my invention thereto except in so far as it is limited by the .scopeo' the claims annexed creto'. A i

'W hat l claiml as new and desire to secure by Letters Patent of the United States, is:

l. A controlling devicefor electric niotors .comprising a starting resistance, en nnbiesed controlling arm therefor, a switch in connection therewith for short-circnitin@the arm when the latter reaches running position, and c latch for-.holding the, switch firmly closed.

E2. A controlling device for electricmotors comprising a starting resistance, an unbiased controlling arm therefor, an automatic circuit-breaker controlled by said arm, a switch in connection With the arm for short-circuiting the same when it reaches runningr position, anda latch for controlling thc circuit-breaker nndvholding `the switch firmly closed.

A controlling device for electric motors comprising' a starting resistance, an unbiased controlling arm therefor, a yielding; switch having)r one member. connected to said arm for short-circuiting the latter whenI it reaches running vposition, anda latch for holdingthe switch member firmly in contact; y Li. il controlling `device for electric nr tors comprising o starting rcsistancc,nn unbiased controlling arm therefor, an automatic circuit-breaker having an nnderload vcoil controlled by said arm, a switch in concoil and holding, the switch. irmlyrclosed.

)l controlling dcvi'cefor elcctric'niotors comprising` a etartingresistance, an nnbiased controlling arin therefor, an antoniatic circuit-breaker controlled by Said arm, means for ypreventing the closing of the eircuit-brcaker until the arm isrnoved to start ing position, a vitch in connection with the arni ior short-circniting the same 'when it reachesrunning position, and a latchbfor controlling the circuit-breaker and holding the switch l'irmly closed. ft', ii. eoneiolling Vdevice for electric motors comprising a starting resistance, un Unbiased controlling arm therefor, un autothe tindex-load coil and holding; thel same matic, circuit-breaker having an-unclerload irmly closed. c 1o coil controlled-by said arm, means for preln witness whereof, I have hereunto set 'venting the closing of the circuibbreakcr my hand this 9th day of June. 1908.

until the arm is moved to starting position, GEORGE H. DORGELOH.

a switch inconnection with the arm for Witnesses:

short-circuiting the saine when it reaches BENJAMIN B. HULL,

' running position, and a latch for controlling HELEN AORFORD. l 

